package problem.nc013;


public class Solution {

    static class TreeNode {
        int val = 0;
        TreeNode left = null;
        TreeNode right = null;
    }

    /**
     *
     * @param root TreeNode类
     * @return int整型
     */
    public int maxDepth (TreeNode root) {
        if (root == null){
            return 0;
        }
        return Math.max(maxDepth(root.left) + 1,maxDepth(root.right) + 1);
    }
}
